Definition: You are given a question on prehistory. You are also given 4 answer options (associated with "A", "B", "C", "D"), out of which only one is correct. You need to answer the question by selecting the correct option. You should only answer with the choice letter, not the whole answer.
Input: What was the Chinese technique of stamped or pounded earth that was used in construction of house walls and defensive structures?
(A)Hang-t'u (B)Scapulimancy (C)Lung-shan (D)Qin manufacture

A